He is perhaps best known for his role as Master Splinter in the 1987 version of Teenage Mutant Ninja Turtles. He has voiced characters in films such as The Aristocats and Scooby-Doo and the Witch's Ghost and has voiced characters in TV shows such as Angel, Grim & Evil, Evil Con Carne, and Justice League. Renaday has also voiced characters in a number of video games, such as Dragon Age: Origins, Ninja Gaiden Sigma 2, Halo Wars, Lost Odyssey, Jeanne d'Arc, James Bond 007: From Russia with Love, Metal Gear Solid 2: Sons of Liberty, and Viewtiful Joe 2.